The most commonly used medications for pain management are narcotics, nonsteroidal anti-inflammatory drugs (NSAIDS) and acetaminophen. Acetaminophen and NSAIDS are used for mild to moderate pain. They have a ceiling effect; beyond a certain dose any additional medication does not produce additional pain relief. Narcotics are mainly used for moderate to severe pain. They have several side effects including nausea, constipation and addiction. There is another group of agents called “adjuvant analgesics” which provide pain relief by a variety of mechanisms. Their primary uses are for disorders such as epilepsy and depression. However, they can also be very useful to provide relief in many painful disorders such as chronic neck pain, chronic back pain, herniated disc, bulging disc, neuropathy, reflex sympathetic dystrophy (RSD), complex regional pain syndrome (CRPS) and shingles. An interventional pain management physician is trained to know these medications and can determine which one may treat your problem.
The first group of drugs is anti-epileptic medications used primarily for the treatment of epilepsy and related disorders. These drugs are most successful in the treatment of neuropathic pain disorders. Neuropathic disorders are painful conditions caused by disease or injury to the nerve itself. Examples of neuropathic disorders include trigeminal neuralgia, reflex sympathetic dystrophy (RSD) and shingles. The mechanism of action of these drugs includes interfering with sodium channels or receptors for the neurotransmitter GABA on the nerve cells. Carbamazepine has been used for many years to treat trigeminal neuralgia. Newer agents include Gabapentin (Neurontin) and Pregabalin (Lyrica) and have a better side effect profile than the older drugs. These drugs are usually started slowly to limit side effects and titrated higher over several weeks.
The next classes of medications are anti-depressants used primarily for the treatment of depression. It was thought initially that these agents treat pain by treating the depression that was caused by chronic pain. However, it was found that these agents have pain relieving properties independent of their effects on mood. Their mechanism of action is related to their effects on chemicals such as norepinephrine and serotonin in the brain. These drugs may reduce the amount of narcotics necessary to achieve any particular level of pain relief. They can also have side effects such as constipation, dry mouth and sedation. A chronic pain management physician can determine which drug can treat your pain best along with the least amount of side effects. Two of the most commonly used drugs are amitriptyline (Elavil) and nortriptyline (Pamelor).
Antipsychotics are a third class of medications used to treat chronic pain. They are useful as adjuvant drugs in the treatment of migraine and neuropathic pain. They are divided into two groups; older typical drugs such as haloperidol (Haldol) and newer atypical drugs such as resperidone (Risperdal). Prolonged use of these medications may cause a side effect called extrapyramidal symptoms as well as dry mouth, blurry vision and constipation.
There are many types of chronic pain disorders. Treatment of pain with medication starts with acetaminophen and non-steroidal anti-inflammatory drugs. Mild narcotics and later potent narcotics are added if the pain is not well controlled. Pain may not be well controlled with these agents alone. When that occurs, the adjuvant analgesics mentioned are a powerful addition to any pain management regimen. An interventional pain management physician can determine which, if any, of these agents are right for your pain.